greenfield



(No Model.) E. T. GREENPIELD.

METALLIC JUNCTION BOX AND. MEANS FOR UNITING METAL GONDUIT TUBES THERETO.

No. 593,841. Patented Nov. 16,1897. 13% Z 80 FT METAL NUT witmv/aoeo a mbew z,

, u. @51 $4; attozwzl I UNITED STATES PATENT FFICE.

EDWIN T. GREENFIELD, OF NEW YORK, N. Y.

METALLIC JUNCTION-BOX AND MEANS FORUNITING METAL CONDUlT-TUBES THERETO.

SPECIFICATION forming part of Letters Patent No. 593,841, dated November 16, 1897. Application filed July 27, 1897. Serial No. 646,100. (No model.)

To a. whom it may concern:

Be it known that I, EDWIN T. GREENFIELD, a citizen of the United States, residing at New York, in the-county of New York and State of New York, have made a new and useful Invention in Metallic J unction-Boxes and Means for Uniting Metal Conduit-Tubes Thereto, of which the following is a specification.

My invention is directed to improvements upon an invention disclosed in a prior patent granted to me on the 27th day of October, 1896, and numbered 570,167; and its object is tosimplify and diminish the expense of the structure of such boxes and the'means of attaching or joining metal or armored conduit-tubes thereto. In the invention disclosed in the patent above referred to thejunction-box itself was made of soft metal and cast under air-pressure in order to enable the same to be made complete, with screw-threads to the necks to which the radiating conduits were to be joined. Such a box, although much cheaper in structure than any known to me prior to its introduction, is still more costly and complicated than the one hereinafter described and claimed by reason of the expensive nature of the metal from which it is constructed, and the entire structure is more costly and cumbersome than that hereinafter described by reason of the fact that a greater. number of parts were required to effect the union between a conduit-tube and the inte gral neck of the j unction-box.

My present invention contemplates the making of the j unction-box of ordinary castiron with screw-threaded necks and the attaching thereto of a conduit-tube by use of a single gripping-nut.

My invention will be fully understood by referring to the accompanying drawings, in which- Figure 1 represents in plan view one of my improved junction-boxes with the cover removed and a pair of metal or armored conduit-tubes joined thereto by the hereinafterdescribed improved means. Fig. 2 is a longitudinal sectional view taken through Fig. 1 on the line 00 0c, the cover of the junctionbox, however, being shown in position in this view and one of the conduit-tubes slightly removed therefrom. Fig. 3 illustrates in perthe integral neck B spective view my improved means of uniting metal or armored conduit-tubes to the screwthreaded necks of a j u nction-box.

Referring now to the drawings in detail, in all of which like letters of reference represent like parts Wherever used, 13 represents a junction-box of common cast-iron, having diametrically-arranged lugs o a, designed to secure the same to the wall, ceiling, or point of support, and b I) represent corresponding lugs by means of which the cover or cap 13 is secured through the agency of screws. This j unction-box is provided with any preferred number of integral necks B B screwthreaded interiorly and having at theirinner ends conical or wedge-shaped surfaces adapted to receive the like conical or wedge-shaped ends or surfaces of a split nut N, longitudinally split at S, as clearly shown in Fig. 3. This split nut N is of soft metal, such as lead or type metal, and its exterior or operative end is either octagonal or round, as preferred, according to the means it is designedto use for screwing it home.

P P are armored conduit-tubes having insulating-linings I of any well-known material, and I represents the interior insulatinglining of the junction-box and its cover, said lining being provided with openings at the points opposite the screw-threaded integral tube is then inserted into the neck B until its inner end assumes the position shown on the left, so that the insulation I of the armored conduit-tube rests firmly against the insulation I of the junction-box. The screwnut N is now advanced by turning it with a wrench, or, if cylindrical, with apipe-wrench, until the conical end thereof abuts firmly against the corresponding conical surface of By reason of the fact that the nut N is of soft metal it will readily adjust itself to the inequalities of the screwthread in the neck B and as it is firmly screwed home it will wedge and grip the end of the tube P and hold it securely in place.

It will thus be seen that I am enabled to effeet the connection between an armored conduit-tube and its j unction-box by the aid of a simple split nut, thereby doing away with the split washer, which constitutes the gripping means of the structure disclosed in my prior patent, above referred to. I am also enabled to protect the screw-threaded parts of the device by reason of the fact that the screwthreads in the integral necks B are interior screw-threads, so that when the nut is screwed home all of the screw-threaded portions are concealed.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

l. A metallic junction-box having one or more integral screw-threaded necks, in combination with a metal conduit-tube and a split nut exteriorly screw threaded and adapted to firmly grip and hold the conduittube in the integral neck, substantially as described.

2. A cast-iron junction-box having one or more integral screw-threaded necks, in combination with a metal conduit-tube and a soft-metal split nut adapted to surround the conduit-tube and firmly grip the same within the integral neck, substantially as described.

A cast-metal junction-box having one or more integral screw-threaded necks, said 3' unction-box being lined with insulating material, in combination with one or more metallic conduit-tubes lined with insulating material and one or more split nuts exteriorly screw-threaded and adapted to unite said conduit tube or tubes to the integral necks, substantially as described.

4. A cast-iron junction-box having one or more integral necks, each interiorly screwthreaded, said junction-box being lined with insulating material, in combination with one or more armored conduit-tubes and a screwthreaded split nut adapted to surround each of said conduit-tubes and firmly unite the same to its corresponding integral neck, substantially as described.

5. A cast-iron junction-box having one or more integral necks interiorly screw-threaded and provided each with a conical surface at its inner end, said junction-box being lined with insulating material, in combination with one or more armored conduit-tubes and a soft-metal split nut adapted to secure each of said conduit-tubes to its corresponding integral neck, said split nut being cone or wedge shaped at its inner end, substantially as described.

(3. A cast-iron junction-box having integral necks screw-threaded interiorly, in combination with an armored conduit-tube and a soft-metal nut screw-threaded exteriorly and adapted, by its wedging action, to unite said conduit-tube to the integral neck, substantially as described.

In testimony whereof I have hereunto subscribed my name this 19th day of July, 1897.

EDWIN T. GREENFIELD.

\Vitnesses:

W. E. MANDELICK, C. J. KINTNER. 

